1. Field of the Invention
The present invention relates to a mobile telephone, and more particularly to a technique for applying a semiconductor memory having a sector data structure to a memory system of the mobile telephone.
2. Description of the Background Art
In recent years, capacities of user data and a firmware tend to be increased more and more with the diversification of a mobile telephone. In a conventional mobile telephone, these data and the like are stored in a random accessible flash memory, for example, a DINOR (divided bit line NOR) type flash memory.
FIG. 16 is a block diagram typically showing a general DINOR type 16 Mbit flash memory 200. As shown in FIG. 16, the flash memory 200 comprises a memory cell array 212, an X-decoder 211, a Y-decoder 207, a Y-gate/sense amplifier 208, a command user interface (command user I/F) 201, a write state machine 221, a status/ID register 222, a multiplexer 203 and an input/output buffer 220. The write state machine 221 controls internal write and the status/ID register 222 holds internal write Pass/Fail and a device ID. Furthermore, the flash memory 200 comprises address terminals A0 to A7 connected to the Y-decoder 207, address terminals A8 to A20 connected to the X-decoder 211, terminals CE#, OE#, WE#, WP and RP# connected to the command user interface 201, a terminal RY/BY# connected to the write state machine 221, and data output terminals D0 to D7 connected to the input/output buffer 220.
In the flash memory 200, contents stored in the memory cell array 212 are read out in the following manner. First of all, the terminals CE# and OE# are set to xe2x80x9cLxe2x80x9d and the terminal WE# is set to xe2x80x9cHxe2x80x9d, and such values are input to the write state machine 221 through the command user interface 201. At this time, an address signal is input to the X-decoder 211 and the Y-decoder 207 through the address terminals A0 to A20. In response to these signals, the write state machine 221, the X-decoder 211, the Y-decoder 207 and the Y-gate/sense amplifier 208 are operated so that data on a desired address are read to the input/output buffer 220 through the multiplexer 203. Consequently, the stored contents are output to the data output terminals D0 to D7.
It is difficult to further increase the capacity of the random accessible flash memory. Thus, it has been hard to correspond to the user data and the firmware having capacities increased more and more.
As one means capable of solving such a problem, it can be proposed that a flash memory having a sector data structure is used in place of the random accessible flash memory. The flash memory is more excellent in an increase in a capacity than the random accessible flash memory.
A read access method of the flash memory is different from that of the random accessible flash memory. More specifically, the stored contents are read out in a sector unit in the flash memory having the sector data structure. Moreover, a read command and a sector address are sequentially input (in time series) so that the contents stored in a sector are read out serially.
For this reason, there is a problem in that the random accessible flash memory cannot be exactly replaced with the flash memory having the sector data structure due to a difference in the read access method.
Furthermore, there is a latency time (read access latency time) during reading in the flash memory having the sector data structure until a sector address is input and read (serial read) can be then carried out. In general, there is also a problem in that the latency time is longer than that in the random accessible flash memory.
These problems make it hard to mount the flash memory having the sector data structure on the conventional mobile telephone.
A first aspect of the present invention is directed to a mobile telephone comprising a controller, a first semiconductor memory which is random accessible and the controller can access, a second semiconductor memory which is connected to the first semiconductor memory and includes a flash memory, and a memory-controller provided between the second semiconductor memory and the controller to connect the second semiconductor memory and the controller and to control the first semiconductor memory and the second semiconductor memory based on a control instruction sent from the controller, wherein the second semiconductor memory has a sector data structure including a plurality of sectors and storing a content in a sector unit, and the memory-controller controls the first semiconductor memory and the second semiconductor memory based on the control instruction sent from the controller, to execute a transfer processing of transferring a predetermined content stored in a predetermined one of the sectors to the first semiconductor memory and storing the predetermined content in the first semiconductor memory.
A second aspect of the present invention is directed to the mobile telephone according to the first aspect of the present invention, wherein the predetermined content has a predetermined recognition number, and the first semiconductor memory stores the predetermined content and the predetermined recognition number.
A third aspect of the present invention is directed to the mobile telephone according to the first aspect of the present invention, wherein the controller retrieves that the predetermined content is stored in the first semiconductor memory or not before giving the control instruction to the memory-controller.
A fourth aspect of the present invention is directed to the mobile telephone according to the second aspect of the present invention, wherein the controller retrieves that the predetermined recognition number is stored in the first semiconductor memory or not before giving the control instruction to the memory-controller.
A fifth aspect of the present invention is directed to the mobile telephone according to the first to fourth aspects of the present invention, wherein the first semiconductor memory has a capacity for at least two of the sectors.
A sixth aspect of the present invention is directed to the mobile telephone according to the first to fifth aspects of the present invention, wherein the memory-controller has a register for the controller to write the control instruction and resets a value of the register after the transfer processing is ended.
According to the first aspect of the present invention, the memory-controller transfers the predetermined content in the second semiconductor memory to the first semiconductor memory and stores the same content in the first semiconductor memory in response to the control instruction of the controller. Consequently, the controller can utilize the predetermined content by accessing the first semiconductor memory in place of the second semiconductor memory. Therefore, also in the case in which different access methods are used for the second semiconductor memory and the first semiconductor memory, such a difference can be absorbed and the controller does not need to use or properly use the two kinds of access methods. In this case, it is possible to easily increase a memory capacity of the whole mobile telephone with an increase in a capacity of the second semiconductor memory.
According to the second aspect of the present invention, the content stored in the first semiconductor memory can be specified based on the recognition number. Consequently, the controller can know whether the predetermined (desired) content is stored in the first semiconductor memory or not before giving the control instruction to the memory-controller. As a result, it is possible to prevent an unnecessary or repetitive transfer processing for the stored content. Moreover, the controller does not need to finely grasp the whole first semiconductor memory through the use of the recognition number.
According to the third aspect of the present invention, in the case in which the predetermined content is stored in the first semiconductor memory, the controller can access the first semiconductor memory to utilize the predetermined content without giving an instruction for the transfer processing to the memory-controller. Accordingly, it is possible to implement a processing at a higher speed by omitting a time required for the transfer processing from the second semiconductor memory to the first semiconductor memory.
According to the fourth aspect of the present invention, the controller can confirm the content stored in the first semiconductor memory based on the recognition number. Therefore, the same effects as those in the third aspect of the present invention can be obtained. By using the recognition number, particularly, the controller does not need to finely retrieve the whole first semiconductor memory.
According to the fifth aspect of the present invention, the first semiconductor memory can store the contents for a plurality of sectors. Therefore, the controller can utilize a plurality of contents at the same time or in parallel. Consequently, the controller does not need to carry out an interruption processing for the transfer processing in the middle of the processing.
According to the sixth aspect of the present invention, the controller can know the end of the transfer processing based on the fact that the value of the register of the memory-controller is reset. Consequently, the controller can properly know that the predetermined content is set in an available state in the first semiconductor memory.
In consideration of such a respect, it is an object of the present invention to provide a mobile telephone comprising a semiconductor memory having a sector data structure.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.